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Diffstat (limited to 'arch')
-rw-r--r--arch/arm/include/asm/ftrace.h3
-rw-r--r--arch/arm/include/asm/module.h1
-rw-r--r--arch/arm/kernel/ftrace.c46
-rw-r--r--arch/arm/kernel/module-plts.c44
4 files changed, 82 insertions, 12 deletions
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
index 48ec1d0337da..a4dbac07e4ef 100644
--- a/arch/arm/include/asm/ftrace.h
+++ b/arch/arm/include/asm/ftrace.h
@@ -15,6 +15,9 @@ extern void __gnu_mcount_nc(void);
#ifdef CONFIG_DYNAMIC_FTRACE
struct dyn_arch_ftrace {
+#ifdef CONFIG_ARM_MODULE_PLTS
+ struct module *mod;
+#endif
};
static inline unsigned long ftrace_call_adjust(unsigned long addr)
diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h
index 09b9ad55b83d..cfffae67c04e 100644
--- a/arch/arm/include/asm/module.h
+++ b/arch/arm/include/asm/module.h
@@ -30,6 +30,7 @@ struct plt_entries {
struct mod_plt_sec {
struct elf32_shdr *plt;
+ struct plt_entries *plt_ent;
int plt_count;
};
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 61de8172a044..3c83b5d29697 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -68,9 +68,10 @@ int ftrace_arch_code_modify_post_process(void)
return 0;
}
-static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr,
+ bool warn)
{
- return arm_gen_branch_link(pc, addr, true);
+ return arm_gen_branch_link(pc, addr, warn);
}
static int ftrace_modify_code(unsigned long pc, unsigned long old,
@@ -104,14 +105,14 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
int ret;
pc = (unsigned long)&ftrace_call;
- new = ftrace_call_replace(pc, (unsigned long)func);
+ new = ftrace_call_replace(pc, (unsigned long)func, true);
ret = ftrace_modify_code(pc, 0, new, false);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
if (!ret) {
pc = (unsigned long)&ftrace_regs_call;
- new = ftrace_call_replace(pc, (unsigned long)func);
+ new = ftrace_call_replace(pc, (unsigned long)func, true);
ret = ftrace_modify_code(pc, 0, new, false);
}
@@ -124,10 +125,22 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long new, old;
unsigned long ip = rec->ip;
+ unsigned long aaddr = adjust_address(rec, addr);
+ struct module *mod = NULL;
+
+#ifdef CONFIG_ARM_MODULE_PLTS
+ mod = rec->arch.mod;
+#endif
old = ftrace_nop_replace(rec);
- new = ftrace_call_replace(ip, adjust_address(rec, addr));
+ new = ftrace_call_replace(ip, aaddr, !mod);
+#ifdef CONFIG_ARM_MODULE_PLTS
+ if (!new && mod) {
+ aaddr = get_module_plt(mod, ip, aaddr);
+ new = ftrace_call_replace(ip, aaddr, true);
+ }
+#endif
return ftrace_modify_code(rec->ip, old, new, true);
}
@@ -140,9 +153,9 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long new, old;
unsigned long ip = rec->ip;
- old = ftrace_call_replace(ip, adjust_address(rec, old_addr));
+ old = ftrace_call_replace(ip, adjust_address(rec, old_addr), true);
- new = ftrace_call_replace(ip, adjust_address(rec, addr));
+ new = ftrace_call_replace(ip, adjust_address(rec, addr), true);
return ftrace_modify_code(rec->ip, old, new, true);
}
@@ -152,12 +165,29 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
+ unsigned long aaddr = adjust_address(rec, addr);
unsigned long ip = rec->ip;
unsigned long old;
unsigned long new;
int ret;
- old = ftrace_call_replace(ip, adjust_address(rec, addr));
+#ifdef CONFIG_ARM_MODULE_PLTS
+ /* mod is only supplied during module loading */
+ if (!mod)
+ mod = rec->arch.mod;
+ else
+ rec->arch.mod = mod;
+#endif
+
+ old = ftrace_call_replace(ip, aaddr,
+ !IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || !mod);
+#ifdef CONFIG_ARM_MODULE_PLTS
+ if (!old && mod) {
+ aaddr = get_module_plt(mod, ip, aaddr);
+ old = ftrace_call_replace(ip, aaddr, true);
+ }
+#endif
+
new = ftrace_nop_replace(rec);
ret = ftrace_modify_code(ip, old, new, true);
diff --git a/arch/arm/kernel/module-plts.c b/arch/arm/kernel/module-plts.c
index d330e9ec2de3..a0524ad84e4d 100644
--- a/arch/arm/kernel/module-plts.c
+++ b/arch/arm/kernel/module-plts.c
@@ -4,6 +4,7 @@
*/
#include <linux/elf.h>
+#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sort.h>
@@ -20,19 +21,52 @@
(PLT_ENT_STRIDE - 8))
#endif
+static const u32 fixed_plts[] = {
+#ifdef CONFIG_FUNCTION_TRACER
+ FTRACE_ADDR,
+ MCOUNT_ADDR,
+#endif
+};
+
static bool in_init(const struct module *mod, unsigned long loc)
{
return loc - (u32)mod->init_layout.base < mod->init_layout.size;
}
+static void prealloc_fixed(struct mod_plt_sec *pltsec, struct plt_entries *plt)
+{
+ int i;
+
+ if (!ARRAY_SIZE(fixed_plts) || pltsec->plt_count)
+ return;
+ pltsec->plt_count = ARRAY_SIZE(fixed_plts);
+
+ for (i = 0; i < ARRAY_SIZE(plt->ldr); ++i)
+ plt->ldr[i] = PLT_ENT_LDR;
+
+ BUILD_BUG_ON(sizeof(fixed_plts) > sizeof(plt->lit));
+ memcpy(plt->lit, fixed_plts, sizeof(fixed_plts));
+}
+
u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val)
{
struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :
&mod->arch.init;
+ struct plt_entries *plt;
+ int idx;
+
+ /* cache the address, ELF header is available only during module load */
+ if (!pltsec->plt_ent)
+ pltsec->plt_ent = (struct plt_entries *)pltsec->plt->sh_addr;
+ plt = pltsec->plt_ent;
- struct plt_entries *plt = (struct plt_entries *)pltsec->plt->sh_addr;
- int idx = 0;
+ prealloc_fixed(pltsec, plt);
+
+ for (idx = 0; idx < ARRAY_SIZE(fixed_plts); ++idx)
+ if (plt->lit[idx] == val)
+ return (u32)&plt->ldr[idx];
+ idx = 0;
/*
* Look for an existing entry pointing to 'val'. Given that the
* relocations are sorted, this will be the last entry we allocated.
@@ -180,8 +214,8 @@ static unsigned int count_plts(const Elf32_Sym *syms, Elf32_Addr base,
int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
char *secstrings, struct module *mod)
{
- unsigned long core_plts = 0;
- unsigned long init_plts = 0;
+ unsigned long core_plts = ARRAY_SIZE(fixed_plts);
+ unsigned long init_plts = ARRAY_SIZE(fixed_plts);
Elf32_Shdr *s, *sechdrs_end = sechdrs + ehdr->e_shnum;
Elf32_Sym *syms = NULL;
@@ -236,6 +270,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
mod->arch.core.plt->sh_size = round_up(core_plts * PLT_ENT_SIZE,
sizeof(struct plt_entries));
mod->arch.core.plt_count = 0;
+ mod->arch.core.plt_ent = NULL;
mod->arch.init.plt->sh_type = SHT_NOBITS;
mod->arch.init.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
@@ -243,6 +278,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
mod->arch.init.plt->sh_size = round_up(init_plts * PLT_ENT_SIZE,
sizeof(struct plt_entries));
mod->arch.init.plt_count = 0;
+ mod->arch.init.plt_ent = NULL;
pr_debug("%s: plt=%x, init.plt=%x\n", __func__,
mod->arch.core.plt->sh_size, mod->arch.init.plt->sh_size);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 19:09:04 +0000